TW202045680A - Thermoconductive composition and semiconductor device - Google Patents

Abstract

A thermally conductive composition of the present invention comprises: metal particles; a binder resin; and a monomer; wherein the metal particle is sintered by thermal treatment to form a particle connection structure, and satisfies the equation 0.35 ≤ [lambda]/(E2) wherein [lambda] (W/mK) denotes a thermal conductivity and E (GPa) denotes a storage modulus at 25 DEG C.

Description

Thermal conductive composition and semiconductor device

The invention relates to a thermally conductive composition and a semiconductor device.

So far, various developments have been made in thermally conductive compositions. As these technologies, for example, the technologies described in Patent Document 1 and Patent Document 2 are known. Patent Document 1 describes a thermosetting resin composition for semiconductor bonding containing a (meth)acrylate compound, a radical initiator, silver particles, silver powder, and a solvent (Technical Solution 1 of Patent Document 1). It has the following description: It is possible to realize the bonding of a semiconductor element and a metal substrate by silver particles heated to 200°C (paragraph 0001, 0007, etc.).

On the other hand, Patent Document 2 describes a resin paste composition containing an epoxy resin, a curing agent, a curing accelerator, a diluent, and silver powder (Table 1 of Patent Document 2). There is a description that the resin paste composition can be cured at 150° C., and the semiconductor element and the supporting member can be bonded with a cured product such as epoxy resin (paragraph 0038, etc.).

Patent Document 1: Japanese Patent Application Publication No. 2014-74132 Patent Document 2: Japanese Patent Application Publication No. 2000-239616

However, as a result of research conducted by the present inventors, it is clear that the compositions described in Patent Document 1 and Patent Document 2 have room for improvement in terms of thermal cycle characteristics and heat dissipation.

As a result of further research by the present inventors, they found that when a thermally conductive composition is used for bonding a semiconductor element and a supporting substrate, by appropriately controlling the thermal conductivity and storage elastic modulus of the thermally conductive composition, it is possible to Improve the thermal cycle characteristics of semiconductor devices.

However, the type (hereinafter referred to as sintered type.) that connects the semiconductor element and the supporting substrate by the bonding of heat-treated silver particles can increase the thermal conductivity, but on the contrary, the storage elastic modulus becomes higher, and the thermal cycle characteristics are It may drop. On the other hand, the type (hereinafter referred to as the adhesive type.) that connects the semiconductor element and the supporting substrate by curing components such as epoxy resin that has been cured can reduce the storage elastic modulus to a low level, but conducts heat on the contrary The heat dissipation rate may decrease. That is, with regard to the conventional sintered type and adhesive type, high thermal conductivity and low storage elastic modulus show a trade-off relationship, and it has not been fully studied to balance the increase of thermal conductivity and the decrease of storage elastic modulus.

Based on this insight, the results of further in-depth research have made it clear that by using both the sintered type and the binder type, and appropriately selecting metal particles, the thermal conductivity can be improved while reducing the storage elastic modulus, and by setting the thermal conductivity When it is λ (W/mK) and the storage elastic modulus is E (GPa), λ/(E ² ) is applied as an index, and the thermal cycle characteristics can be evaluated stably. As a result of further research, it was found that by appropriately selecting the value range of λ/(E ² ) as the index, and using this thermally conductive composition for the bonding of the semiconductor element and the supporting substrate, the semiconductor device can be improved The thermal cycle characteristics and heat dissipation properties of the invention have been completed.

According to the present invention, there is provided a thermally conductive composition comprising: metal particles; a binder resin; and a monomer. The metal particles are sintered by heat treatment to form a particle-connected structure. The thermally conductive composition is used according to the following The thermal conductivity λ (W/mK) measured in step A and the storage elastic modulus E (GPa) at 25°C measured in step B below satisfy the following formula (I). 0.35≤λ/(E ² )……Formula (I) (Step A) The thermally conductive composition was heated from 30°C to 200°C in 60 minutes, and then heat-treated at 200°C for 120 minutes to obtain a heat-treated body with a thickness of 1 mm . For the obtained heat-treated body, use the laser flash method to measure the thermal conductivity λ (W/mK) at 25°C. (Step B) The thermally conductive composition was heated from 30°C to 200°C over 60 minutes, and then heat-treated at 200°C for 120 minutes to obtain a heat-treated body. For the heat-treated body obtained, the dynamic viscoelasticity measurement (DMA) at a frequency of 1 Hz was used to measure the storage elastic modulus E (MPa) at 25°C.

Moreover, according to the present invention, there is provided a semiconductor device including: Substrate; and A semiconductor element in which an adhesive layer obtained by heat-treating the above-mentioned thermally conductive composition is mounted on the aforementioned substrate. [Invention Effect]

According to the present invention, a thermally conductive composition having excellent thermal cycle characteristics and heat dissipation properties and a semiconductor device using the same are provided.

Hereinafter, the embodiments of the present invention will be described using drawings. In addition, in all the drawings, the same constituent elements are denoted by the same reference numerals, and the description is appropriately omitted. In addition, the drawing is a schematic drawing and does not match the actual size ratio.

The outline of the thermally conductive composition of this embodiment will be described. The thermally conductive composition of the present embodiment contains metal particles, a binder resin, and a monomer, and the metal particles are sintered by heat treatment to form a particle-connected structure. In the thermally conductive composition, the thermal conductivity measured according to the following step A is set to λ (W/mK), and the storage elastic modulus at 25°C measured according to the following step B is set to E (GPa) When, λ and E satisfy the following formula (I). 0.35≤λ/(E ² )……Formula (I)

(Step A) It took 60 minutes to raise the temperature of the thermally conductive composition from 30°C to 200°C, and then heat-treated at 200°C for 120 minutes to obtain a heat-treated body with a thickness of 1 mm. For the obtained heat-treated body, use the laser flash method to measure the thermal conductivity λ (W/mK) at 25°C. (Step B) This thermally conductive composition was heated up from 30°C to 200°C over 60 minutes, and then heat-treated at 200°C for 120 minutes to obtain a heat-treated body. For the heat-treated body obtained, the dynamic viscoelasticity measurement (DMA) at a frequency of 1 Hz was used to measure the storage elastic modulus E (MPa) at 25°C.

Based on the findings of the present inventors, it was found that by using the above-mentioned sintered type and binder type at the same time, and appropriately selecting metal particles, it is possible to increase the thermal conductivity and reduce the storage elastic modulus. Although the detailed mechanism is not yet clear, it is believed that the adhesive layer formed by curing the thermally conductive composition has a particle-connected structure (sintered structure) of metal particles, so the thermal conductivity is higher than that of the adhesive type, and resins such as adhesive resin remain. Composition, so the storage elastic modulus is lower than that of sintered type. Furthermore, it is considered that by using metal-coated resin particles in which a metal is coated on the surface of the resin particles as the metal particles, it is possible to appropriately reduce the storage elastic modulus while suppressing the decrease in the sinterability of the metal particles. In addition, the adhesive layer can bond the semiconductor element and the supporting substrate by bonding of metal particles and adhesive resin, and therefore can achieve good adhesion.

Furthermore, based on the findings of the present inventors, it is clarified that by setting the thermal conductivity as λ (W/mK) and the storage elastic modulus as E (GPa), λ/(E ² ) is applied as an index, The thermal cycle characteristics can be evaluated stably. As a result of further research, it was found that by setting λ/(E ² ) as the index to be higher than the lower limit value, the thermal conductivity composition can be used to bond a semiconductor element and a supporting substrate. Improve the thermal cycle characteristics of semiconductor devices.

The lower limit of the aforementioned λ/(E ² ) is 0.35 or more, preferably 0.37 or more, and more preferably 0.40 or more. Thereby, the thermal cycle characteristics can be improved. On the other hand, the upper limit of the aforementioned λ/(E ² ) may be 3.0 or less, 2.0 or less, or 1.5 or less, for example.

In addition, the lower limit of the thermal conductivity of the heat-treated body of the thermally conductive composition in the thickness direction at 25°C is, for example, 10 W/mK or more, preferably 15 W/mK or more, and more preferably 20 W/mK or more. Thereby, the high heat dissipation property of the adhesive layer using the said thermally conductive composition can be achieved. On the other hand, the upper limit of the thermal conductivity of the heat-treated body of the thermally conductive composition may be, for example, 200 W/mK or less, or may be 150 W/mK or less.

In addition, the upper limit of the storage elastic modulus E (GPa) is, for example, 15.0 GPa or less, preferably 8.5 GPa or less, and more preferably 7.0 GPa or less. This can further improve the thermal cycle characteristics. The lower limit of the storage elastic modulus E (GPa) is not particularly limited, but for example, it may be 0.1 GPa or more or 0.5 GPa or more.

In addition, the resin content in the heat-treated body obtained by the following procedure is, for example, 10% by mass or more and 30% by mass or less, preferably 12% by mass or more and 29% by mass or less, relative to 100% by mass of the heat-treated body. By setting in this range of values, the storage elastic modulus and thermal conductivity can be balanced. (step) This thermally conductive composition was heated up from 30°C to 200°C over 60 minutes, and then heat-treated at 200°C for 120 minutes to obtain a heat-treated body. The resin content can be calculated by measuring the weight of the obtained heat-treated body and subtracting the weight of silver contained from the weight. The resin component of the target of the resin content includes a resin component derived from a binder resin and a resin component derived from a metal coating resin particle, and any one or both of these may be included.

In this embodiment, for example, by appropriately selecting the type, blending amount, and preparation method of each component contained in the thermally conductive composition, the above-mentioned λ/(E ² ), λ, and resin can be controlled. The residual amount. Among these, as the requirements for setting the above-mentioned λ/(E ² ), λ and the residual amount of the resin within the desired numerical range, for example, the use of a sintered composition system and a binder-type composition system at the same time; And appropriately select the use of metal coating resin particles, the particle size/content and other metal particles.

The thermally conductive composition of the present embodiment can be used for various applications, but can be applied to applications requiring heat dissipation and adhesiveness of electronic parts such as semiconductor elements. Specifically, the thermally conductive composition is interposed between electronic parts such as semiconductor elements and metal members such as lead frames, and can be used to form an adhesive layer for bonding them. The adhesive layer is composed of a heat-treated body of a thermally conductive composition.

According to this embodiment, by using the adhesive layer formed of the heat-treated body of the above-mentioned thermally conductive composition, the thermal cycle characteristics in the semiconductor device can be improved. In addition, high heat dissipation of the semiconductor element can be achieved. This high heat dissipation performance can be stably realized.

Hereinafter, each component of the thermally conductive composition of this embodiment will be described in detail.

The thermally conductive composition of this embodiment contains the aforementioned metal particles, binder resin, and monomers. Although the detailed mechanism is not clear, it is thought that if the volume of the composition shrinks due to the volatilization of monomers due to heating, stress is applied in the direction in which the metal particles approach each other, and the interface between the metal particles disappears, forming a connection structure of the metal particles. In addition, it is considered that when such metal particles are sintered, the binder resin, or the resin cured product such as the binder resin and the curing agent or monomer, remains inside or outside the connection structure. Furthermore, it is believed that the hardening reaction generates a force such as agglomeration of a plurality of metal particles.

By hardening the above-mentioned thermally conductive composition, it is possible to realize an adhesive layer containing "a particle-linked structure of metal particles" and "a resin component composed of a binder resin, its hardened product, and resin particles in metal coating resin particles". .

(Metal particles) The thermally conductive composition of this embodiment contains metal particles. The metal particles can be sintered by heat treatment to form a particle connection structure (sintered structure).

The metal particles can use metal-coated resin particles, particles made of metal, and the like. The above-mentioned metal particles may include any of metal-coated resin particles and particles composed of metal, but it is more preferable to include both.

By using the above-mentioned metal-coated resin particles, it is possible to appropriately reduce the storage elastic modulus while suppressing the decrease in the sinterability of the metal particles. By using the above-mentioned particles made of metal, the sinterability of the metal particles can be improved, and the thermal conductivity can be appropriately increased.

The metal-coated resin particles are composed of resin particles and a metal formed on the surface of the resin particles. That is, the metal-coated resin particles may be particles obtained by coating the surface of the resin particles with a metal layer.

In this specification, the surface of the metal layer-coated resin particle refers to the state where the metal layer covers at least a part of the surface of the resin particle, and is not limited to covering the entire surface of the resin particle. For example, it may include a metal layer partially covering the surface. State, covering the whole surface when viewed from a specific section. Among them, from the viewpoint of thermal conductivity, it is preferable that the metal layer covers the entire surface when viewed from a specific cross-section, and it is more preferable to cover the entire surface of the particles.

The metal in the metal-coated resin particles can include, for example, one or more selected from the group consisting of silver, gold, nickel, and tin. These can be used alone or in combination of two or more kinds. Alternatively, alloys containing these metals as main components can be used. Among them, silver can be used from the viewpoint of sinterability and thermal conductivity.

Regarding the resin material constituting the resin particles (core resin particles) in the metal-coated resin particles, for example, silicone, acrylic, phenol, polystyrene, melamine, polyamide, polytetrafluoroethylene, etc. can be cited. These can be used alone or in combination of two or more kinds. The resin particles can be composed of polymers using these. The polymer may be a homopolymer or a copolymer with these as main components. From the standpoint of elastic properties and heat resistance, silicone resin particles and acrylic resin particles can be used as the resin particles.

The above-mentioned polysiloxane resin particles may be particles composed of organopolysiloxane obtained by polymerizing organochlorosilanes such as methylchlorosilane, trimethyltrichlorosilane, dimethyldichlorosilane, etc., or may be A polysiloxane resin particle with a structure formed by further three-dimensional crosslinking of the organopolysiloxane as the basic skeleton.

In addition, various functional groups can be introduced into the structure of the silicone resin particles. Examples of functional groups that can be introduced include epoxy groups, amino groups, methoxy groups, phenyl groups, carboxyl groups, hydroxyl groups, alkyl groups, and vinyl groups. , Mercapto groups, etc., but are not limited to these. In addition, in this embodiment, other low-stress modifiers can be added to the silicone resin particles within a range that does not impair the characteristics. As other low-stress modifiers that can be used simultaneously, butadiene styrene rubber, butadiene acrylonitrile rubber, polyurethane rubber, polyisoprene rubber, acrylic rubber, fluororubber, liquid Liquid synthetic rubbers such as organopolysiloxane and liquid polybutadiene are not limited to these.

The shape of the above-mentioned resin particles is not particularly limited, and may be spherical, but may have a different shape other than a spherical shape, such as a flat shape, a plate shape, and a needle shape. In the case where the shape of the metal-coated resin particles is formed into a spherical shape, it is preferable that the shape of the resin particles used is also spherical. In addition, as described above, the sphere is not limited to a perfect sphere, but also includes a shape close to a sphere such as an ellipse, and a shape with a number of irregularities on the surface.

The lower limit of the specific gravity of the metal-coated resin particles is, for example, 2 or more, preferably 2.5 or more, and more preferably 3 or more. This can further improve the thermal conductivity and electrical conductivity of the adhesive layer. In addition, the upper limit of the specific gravity of the metal-coated resin particles is, for example, 10 or less, preferably 9 or less, and more preferably 8 or less. Thereby, the dispersibility of particles can be improved. The aforementioned specific gravity may be the specific gravity of metal particles including metal-coated resin particles and particles made of metal.

The metal-coated resin particles may be monodisperse particles or polydisperse particles. In addition, in the particle size frequency distribution, the metal-coated resin particles may have one peak or two or more peaks.

The particles composed of metal may be particles composed of one or more types of metal materials, and the core part and the surface layer part may be composed of the same or different types of metal materials. The metal material can include, for example, one or more selected from the group consisting of silver, gold, and copper. These can be used alone or in combination of two or more kinds. Alternatively, alloys containing these metals as main components can be used. Among them, silver can be used from the viewpoint of sinterability and thermal conductivity.

The shape of the particles made of metal may be, for example, a spherical shape or a flake shape. The above-mentioned particles made of metal can include either or both of spherical particles and plate-shaped particles.

Regarding one aspect of the metal particles, the metal-coated resin particles include silver-coated silicone resin particles and metal-made particles include silver particles. In addition to silver-coated silicone resin particles, silver-coated acrylic resin particles can also be used from the viewpoint of elastic properties. In addition to silver particles, particles containing metal components other than silver, such as gold particles, copper particles, etc., can be used at the same time for the purpose of promoting sintering or reducing costs.

The lower limit of the average particle diameter D ₅₀ of the metal-coated resin particles may be, for example, 0.5 μm or more, preferably 1.5 μm or more, and more preferably 2.0 μm or more. Thereby, the storage elastic modulus can be reduced. On the other hand, the upper limit of the average particle diameter D ₅₀ of the metal-coated resin particles may be, for example, 20 μm or less, 15 μm or less, or 10 μm or less. This can improve thermal conductivity. The metallic coating resin particles having an average particle diameter D ₅₀ may be used as a silver coating polyethylene silicone particles, acrylic resin coating the silver particles having an average particle diameter D _50.

The lower limit of the average particle diameter D ₅₀ of the particles made of metal is, for example, 0.8 μm or more, preferably 1.0 μm or more, and more preferably 1.2 μm or more. This can improve thermal conductivity. On the other hand, the upper limit of the average particle diameter D ₅₀ of the particles made of metal is, for example, 7.0 μm or less, preferably 5.0 μm or less, and more preferably 4.0 μm or less. Thereby, the sinterability between metal particles can be improved. In addition, it is possible to improve the uniformity of sintering. The average particle size D _{50 of the} aforementioned metal-made particles can be used as the average particle size D _{50 of the} silver particles.

In addition, the average particle diameter D _{50 of the} metal particles can be determined by, for example, particle image measurement using a flow-type particle image analyzer FPIA (registered trademark)-3000 manufactured by Sysmex Corporation. More specifically, the particle diameter of the metal particles can be determined by measuring the volume-based median diameter using the above-mentioned device.

The content of the metal-coated resin particles is, for example, 1% by mass to 50% by mass, preferably 3% by mass to 45% by mass, more preferably 5% by mass to 40% by mass relative to the entire metal particles (100% by mass) . The storage elastic modulus can be reduced by setting it to be higher than the above lower limit. By setting it below the above upper limit value, the thermal conductivity can be improved.

The content of the metal particles is 1% to 98% by mass relative to the entire thermally conductive composition (100% by mass), preferably 30% to 95% by mass, and more preferably 50% to 90% by mass. By setting it as the above-mentioned lower limit or more, thermal conductivity can be improved. By setting it below the above upper limit value, it is possible to improve coatability and workability at the time of sticking. In this manual, "～" means that the upper limit and the lower limit are included unless otherwise specified.

(Adhesive resin) The said thermally conductive composition contains binder resin. The said binder resin can contain 1 or more types chosen from the group which consists of an epoxy resin, an acrylic resin, and an allyl resin. These can be used alone or in combination of two or more kinds.

Specific examples of the above-mentioned binder resin include: acrylic resins such as acrylic oligomers and acrylic polymers; epoxy resins such as epoxy oligomers and epoxy polymers; allyl oligomers and allyl Allyl resins such as base polymers. These can be used alone or in combination of two or more kinds. In addition, those with a weight average molecular weight of less than 10,000 are defined as oligomers, and those with a weight average molecular weight of 10,000 or more are defined as polymers.

As said epoxy resin, the epoxy resin which has 2 or more epoxy groups in a molecule|numerator can be used. The epoxy resin can be liquid at 25°C. Thereby, the handleability of the thermally conductive composition can be improved. In addition, the hardening shrinkage can be appropriately adjusted.

Regarding specific examples of the aforementioned epoxy resins, for example, trisphenol methane type epoxy resins; hydrogenated bisphenol A type liquid epoxy resins; bisphenol F type liquid epoxy resins such as bisphenol-F-dieglycidyl ether Oxygen resin; o-cresol novolac type epoxy resin, etc. These can be used alone or in combination of two or more kinds. Among them, hydrogenated bisphenol A type liquid epoxy resin or bisphenol F type liquid epoxy resin can be used. As the bisphenol F type liquid epoxy resin, for example, bisphenol-F-dieglycidyl ether can be used.

As the above-mentioned acrylic resin, an acrylic resin having two or more acrylic groups in the molecule can be used. The acrylic resin may be liquid at 25°C. As the acrylic resin, specifically, those obtained by (co)polymerizing an acrylic monomer can be used. Here, the method of (co)polymerization is not limited, and a known method using general polymerization initiators and chain transfer agents, such as solution polymerization, can be used.

As the allyl resin, an allyl resin having two or more allyl groups in one molecule can be used. The allyl resin can be liquid at 25°C.

As said allyl resin, specifically, the allyl ester resin obtained by reacting dicarboxylic acid, allyl alcohol, and the compound which has an allyl group is mentioned. Here, as the above-mentioned dicarboxylic acid, specifically, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, Maleic acid, fumaric acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, etc. In addition, as the compound having the above allyl group, specifically, polyether, polyester, polycarbonate, polyacrylate, polymethacrylate, polybutadiene, butadiene having an allyl group can be mentioned. Acrylonitrile copolymer, etc.

The lower limit of the content of the binder resin with respect to 100 parts by mass of the thermally conductive composition is, for example, 1 part by mass or more, preferably 2 parts by mass or more, and more preferably 3 parts by mass or more. Thereby, the adhesiveness with the adherend can be improved. On the other hand, with respect to 100 parts by mass of the thermally conductive composition, the upper limit of the content of the binder resin is, for example, 15 parts by mass or less, preferably 12 parts by mass or less, and more preferably 10 parts by mass or less. This can suppress a decrease in thermal conductivity.

(monomer) The said thermally conductive composition contains a monomer. Regarding the above-mentioned monomers, one or two or more selected from the group consisting of diol monomers, acrylic monomers, epoxy monomers, and maleimide monomers can be included. These can be used alone or in combination of two or more kinds. By using the above-mentioned monomer, the volatilization state of the above-mentioned thermally conductive composition when heat-treated can be adjusted. In addition, by appropriately selecting the combination with the binder resin and the curing agent, the above-mentioned monomer can undergo a curing reaction with these, and the curing shrinkage state can be adjusted.

Specific examples of the above-mentioned diol monomer include: a diol having two hydroxyl groups in the molecule, and the two hydroxyl groups are bonded to different carbon atoms; the diol and two or more A compound obtained by condensation of an alcohol; a compound obtained by condensation of the alcohol with a hydrogen atom in the hydroxyl group being substituted with an organic group having 1 to 30 carbon atoms to form an alkoxy group.

As the above-mentioned glycol monomer, specifically, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol monoisopropyl ether, ethylene glycol Mono-n-butyl ether, ethylene glycol monoisobutyl ether, ethylene glycol monohexyl ether, ethylene glycol mono-2-ethylhexyl ether, ethylene glycol monoallyl ether, ethylene glycol monophenyl ether, ethylene two Alcohol monobenzyl ether, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, diethylene glycol monoisopropyl ether, diethylene glycol mono-n Butyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monohexyl ether, diethylene glycol mono-2-ethylhexyl ether, diethylene glycol monobenzyl ether, triethylene glycol, triethylene glycol Monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol mono-n-butyl ether, tetraethylene glycol, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetraethylene glycol mono-n-butyl ether, propylene glycol , Propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol monoisopropyl ether, propylene glycol mono-n-butyl ether, propylene glycol monophenyl ether, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol Mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, tripropylene glycol mono-n-butyl ether, etc. These can be used alone or in combination of two or more kinds. Among them, from the viewpoint of volatility, tripropylene glycol mono-n-butyl ether or ethylene glycol mono-n-butyl acetate can be used.

As the lower limit of the boiling point of the aforementioned diol monomer, for example, 100°C or higher is preferred, 130°C or higher is more preferred, 150°C or higher is more preferred, 170°C or higher is even more preferred, and 190°C or higher is particularly preferred. In addition, as the upper limit of the boiling point of the diol monomer, for example, it may be 400°C or lower, or 350°C or lower. In addition, the boiling point of the diol monomer means the boiling point under atmospheric pressure (101.3 kPa).

As said acrylic monomer, the monomer which has a (meth)acrylic group in a molecule|numerator is mentioned. Here, the (meth)acrylic group means an acrylic group and a methacrylic group. The acrylic monomer may be a monofunctional acrylic monomer having only one (meth)acrylic group in the molecule, or a multifunctional acrylic monomer having two or more (meth)acrylic groups in the molecule.

As the above-mentioned monofunctional acrylic monomer, specifically, 2-phenoxyethyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isopropyl (meth)acrylate can be mentioned. Butyl ester, tertiary butyl (meth)acrylate, isoamyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, n-laurel (meth)acrylate Esters, n-tridecyl (meth)acrylate, n-stearyl (meth)acrylate, isostearyl (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, butoxy Diethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, 2-ethylhexyl diethylene glycol (meth)acrylate, methoxy polyethylene glycol ( Meth) acrylate, methoxydipropylene glycol (meth)acrylate, cyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, benzyl (meth)acrylate, (meth)acrylic acid Phenoxyethyl, phenoxydiethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, nonylphenol ethylene oxide modified (meth)acrylate, benzene Base phenol ethylene oxide modification (meth)acrylate, (meth)isobornyl acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, (meth)acrylate Base) dimethylaminoethyl acrylate quaternary compound, glycidyl (meth)acrylate, neopentyl glycol (meth)acrylate benzoate, 1,4-cyclohexanedimethanol mono(methyl) ) Acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxy (meth)acrylate Propyl ester, 2-(meth)acryloxyethyl succinic acid, 2-(meth)acryloxyethylhexahydrophthalic acid, 2-(meth)acryloxyethyl phthalic acid, 2- (Methyl)acryloxyethyl-2-hydroxyethylphthalic acid and 2-(meth)acryloxyethyl acid phosphate, etc.

Specific examples of the multifunctional acrylic monomer include ethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and propoxylated bisphenol A bis(meth) Acrylate, hexane-1,6-diol bis(2-(meth)acrylate), 4,4'-isopropylidene diphenol bis(meth)acrylate, 1,3-butanedi Alcohol di(meth)acrylate, 1,6-bis((meth)acryloyloxy)-2,2,3,3,4,4,5,5-octafluorohexane, 1,4- Bis((meth)acryloxy)butane, 1,6-bis((meth)acryloxy)hexane, triethylene glycol di(meth)acrylate, neopentyl glycol di( Meth)acrylate, neopentyl glycol di(meth)acrylate, N,N'-bis(meth)acryloylethylenediamine, N,N'-(1,2-dihydroxyethylene)bis (Meth)acrylamide or 1,4-bis((meth)acryloyl)piperidin, etc.

As the acrylic monomer, a monofunctional acrylic monomer or a multifunctional acrylic monomer can be used alone, or a monofunctional acrylic monomer and a multifunctional acrylic monomer can be used together. As the acrylic monomer, for example, it is preferable to use a multifunctional acrylic monomer alone.

The above-mentioned epoxy monomer is a monomer having an epoxy group in the molecule. The epoxy monomer may be a monofunctional epoxy monomer having only one epoxy group in the molecule, or a multifunctional epoxy monomer having two or more epoxy groups in the molecule.

As the above-mentioned monofunctional epoxy monomer, specifically, 4-tertiary butylphenyl glycidyl ether, m-cresol glycidyl ether, p-cresol glycidyl ether, Phenyl glycidyl ether, cresyl glycidyl ether, etc.

Specific examples of the above-mentioned polyfunctional epoxy monomer include: bisphenol compounds such as bisphenol A, bisphenol F, and biphenol or derivatives thereof; hydrogenated bisphenol A, hydrogenated bisphenol F, hydrogenated bisphenol Phenol, cyclohexanediol, cyclohexanedimethanol, cyclohexanedimethanol, and other diols with alicyclic structure or their derivatives; using butanediol, hexanediol, octanediol, nonanediol Aliphatic diols such as decanediol, or derivatives of these difunctional ones obtained by epoxidation; those having tri-functional trihydroxyphenylmethane skeleton and aminophenol skeleton; using novolak resin, cresol phenolic Varnish resins, phenol aralkyl resins, biphenyl aralkyl resins, naphthol aralkyl resins and other polyfunctional ones obtained by epoxidation.

The above-mentioned maleimide monomer is a monomer having a maleimide ring in the molecule. The above-mentioned maleimide monomer may be a monofunctional maleimide monomer having only one maleimide ring in the molecule, or it may have two or more in the molecule The multifunctional maleimide monomer of the maleimide ring. Specific examples of the maleimide monomer include polytetramethylene ether glycol-bis(2-maleimide acetate) and the like.

The lower limit of the content of the above-mentioned monomer with respect to 100 parts by mass of the thermally conductive composition is, for example, 0.5 parts by mass or more, preferably 1.0 parts by mass or more, and more preferably 2.0 parts by mass or more. On the other hand, with respect to 100 parts by mass of the thermally conductive composition, the upper limit of the content of the monomer is, for example, 10 parts by mass or less, preferably 7 parts by mass or less, and more preferably 5 parts by mass or less.

(hardener) If necessary, the above-mentioned thermally conductive composition may contain a hardening agent. The above-mentioned hardener has a reactive group that reacts with the monomer and the functional group in the binder resin. As the reactive group, for example, an epoxy group, a maleimide group, a hydroxyl group, etc. reacted with a functional group can be used.

Specifically, in the case where the monomer contains an epoxy monomer or/and the binder resin contains an epoxy resin, a phenol resin-based curing agent or an imidazole-based curing agent can be used as the above-mentioned curing agent.

Specific examples of the phenol resin curing agent include novolac type phenol resins such as novolak resin, cresol novolak resin, bisphenol novolak resin, and phenol-biphenol novolak resin; polyvinyl phenol; three Multifunctional phenol resins such as phenylmethane type phenol resin; modified phenol resins such as terpene modified phenol resin, dicyclopentadiene modified phenol resin, etc.; phenol aromatic with phenylene skeleton and/or biphenylene skeleton Phenol aralkyl type phenol resins such as alkyl resins and naphthol aralkyl resins with phenylene and/or biphenylene skeletons; bisphenol compounds such as bisphenol A and bisphenol F (dihydroxydiphenylmethane) (Phenolic resin with bisphenol F skeleton); 4,4'-biphenol and other compounds with biphenylene skeleton. These can be used alone or in combination of two or more kinds. Among them, phenol aralkyl resin can be used, and as phenol aralkyl resin, phenol and p-stubble dimethyl ether condensation polymer can be used.

As the imidazole curing agent, specifically, 2-phenyl-1H-imidazole-4,5-dimethanol, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-methyl Imidazole, 2-Phenylimidazole, 2,4-Diamine-6-[2-Methylimidazolyl-(1)]-Ethyl-Symmetric Tris, 2-Undecylimidazole, 2-Heptadecylimidazole , 2,4-Diamine-6-[2-Methylimidazolyl-(1)]-ethyl-symmetric triisocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct Product, 2-methylimidazole isocyanuric acid adduct, 1,2,4- trimellitic acid 1-cyanoethyl-2-phenylimidazolium, 1,2,4- trimellitic acid 1- Cyanoethyl-2-undecylimidazolium and the like. These can be used alone or in combination of two or more kinds.

The content of the curing agent may be, for example, 5 parts by mass to 50 parts by mass, or 20 parts by mass to 40 parts by mass relative to 100 parts by mass of the binder resin in the thermally conductive composition. In addition, the content of the curing agent may be, for example, 1 part by mass to 40 parts by mass, or may be 100 parts by mass of epoxy resin in the thermally conductive composition or 100 parts by mass of the total of epoxy resin and epoxy monomer 10 parts by mass to 35 parts by mass.

(Free radical polymerization initiator) The above-mentioned thermally conductive composition may contain a radical polymerization initiator. As the radical polymerization initiator, azo compounds, peroxides, and the like can be used.

Specific examples of the above-mentioned peroxide include bis(1-phenyl-1-methylethyl) peroxide, 1,1-bis(1,1-dimethylethylperoxy) ring Hexane, methyl ethyl ketone peroxide, cyclohexane peroxide, acetone peroxide, 1,1-bis(tertiary hexylperoxy) cyclohexane, 1,1-bis(tertiary) Butylperoxy)-2-methylcyclohexane, 1,1-bis(tertiary butylperoxy)cyclohexane, 2,2-bis(tertiarybutylperoxy)butane, n-butyl -4,4-bis(tertiary butylperoxy) valerate, 2,2-bis(4,4-bis(tertiary butylperoxy)cyclohexane) propane, p-methane hydroperoxide, Diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, tertiary butyl hydroperoxide, two (2-tri -Butylperoxyisopropyl)benzene, dicumyl peroxide, 2,5-dimethyl-2,5-bis(tertiary butylperoxy)hexane, tertiary butyl isopropyl Phenyl peroxide, di-tertiary butyl peroxide, 2,5-dimethyl 2,5-di(tertiary butyl peroxy) hexane, diisobutyl peroxide, di(3 ,5,5-Trimethylhexyl) peroxide, dilauryl peroxide, bis(3-methylbenzyl) peroxide, benzyl(3-methylbenzyl) peroxide Base) peroxide, dibenzyl peroxide, bis(4-methylbenzyl) peroxide, di-n-propyl peroxy dicarbonate, diisopropyl peroxy dicarbonate, Di(2-ethylhexyl)peroxydicarbonate, di-secondary butylperoxydicarbonate, cumyl peroxyneodecanoate, 1,1,3,3-tetramethylbutyl Peroxy neodecanoate, tertiary hexyl neodecanoate, tertiary butyl peroxy neoheptanoate, tertiary hexyl peroxy pivalate, 1,1,3,3-tetramethyl butyl peroxy Oxy-2-ethylhexanoate, 2,5-dimethyl-2,5-bis(2-diethylhexylperoxy)hexane, tertiary butylperoxy-2-ethylhexyl Ester, tertiary hexylperoxyisopropyl monocarbonate, tertiary butylperoxymaleic acid, tertiary butylperoxy 3,5,5-trimethylhexanoate, tertiary butyl Peroxyisopropyl monocarbonate, tertiary butylperoxy-2-ethylhexyl monocarbonate, tertiary hexylperoxybenzoate, 2,5-dimethyl-2,5-bis(benzene Methyl peroxy) hexane, tertiary butyl peroxypyruvate, tertiary peroxy-3-methyl benzoate, tertiary butyl peroxybenzoate, tertiary butyl peroxy allyl Monocarbonate, 3,3',4,4'-tetra(tertiary butylperoxyhydroxy) diphenyl ketone, etc. These can be used alone or in combination of two or more kinds.

(Hardening accelerator) The above-mentioned thermally conductive composition may contain a hardening accelerator. The above-mentioned hardening accelerator can promote the reaction between the binder resin or monomer and the hardening agent.

Specific examples of the curing accelerator include: organic phosphines, tetra-substituted phosphonium compounds, phosphobetaine compounds, adducts of phosphine compounds and quinone compounds, adducts of phosphonium compounds and silane compounds Compounds containing phosphorus atoms; dicyandiamine, 1,8-diazebicyclo[5.4.0]undecene-7, benzyldimethylamine and other amidino and tertiary amines; the above amidino or the above tertiary Nitrogen-containing compounds such as quaternary ammonium salts of amines. These can be used alone or in combination of two or more kinds.

(Silicane coupling agent) The said thermally conductive composition may contain a silane coupling agent. The above-mentioned silane coupling agent can improve the adhesion between the adhesive layer using the thermally conductive composition and the substrate or semiconductor element.

As the silane coupling agent, specifically, vinyl silanes such as vinyl trimethoxy silane and vinyl triethoxy silane; 2-(3,4-epoxycyclohexyl) ethyl trimethoxy silane can be used. , 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-epoxy Propoxy propyl methyl diethoxy silane, 3-glycidoxy propyl triethoxy silane and other siloxane oxides; p-styryl trimethoxy silane and other styryl silanes; 3-methyl Acrylicoxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methyl Methacryloxysilanes such as acryloxypropyltriethoxysilane; Acrylic silanes such as 3-(trimethoxysilyl)propyl methacrylate and 3-acryloxypropyltrimethoxysilane ; N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyl Trimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylene) propylamine, N-phenyl-γ-amine Amino silanes such as propyl trimethoxysilane; triisocyanate silane; alkyl silanes; ureido silanes such as 3-ureidopropyl trialkoxy silane; 3-mercaptopropyl methyl dimethoxy silane, 3 -Mercapto propyl trimethoxy silane and other mercapto silanes; 3-isocyanate propyl triethoxy silane and other isocyanate silanes. These can be used alone or in combination of two or more kinds.

(Plasticizer) The said thermally conductive composition may contain a plasticizer. By adding a plasticizer, the stress can be reduced. As the above-mentioned plasticizer, specifically, polysiloxane compounds such as silicone oil and silicone rubber; polybutadiene compounds such as polybutadiene maleic anhydride adducts; acrylonitrile butadiene Diene copolymer compounds, etc. These can be used alone or in combination of two or more kinds.

(Other ingredients) In addition to the above-mentioned components, the above-mentioned thermally conductive composition may also contain other components as needed. As other components, for example, a solvent can be mentioned.

The solvent is not particularly limited, but examples include ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, ethylene glycol monomethyl ether, and ethylene glycol. Monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, methyl methoxybutanol, α-terpineol, Alcohols such as β-terpineol, hexylene glycol, benzyl alcohol, 2-phenylethanol, isopalmitol, isostearyl alcohol, lauryl alcohol, ethylene glycol, propylene glycol, butyl glycerol or glycerol; acetone , Methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, diacetone alcohol (4-hydroxy-4-methyl-2-pentanone), 2-octanone, isophorone (3,5 ,5-trimethyl-2-cyclohexene-1-one) or diisobutyl ketone (2,6-dimethyl-4-heptanone) and other ketones; ethyl acetate, butyl acetate, phthalein Diethyl phthalate, dibutyl phthalate, acetoxyethane, methyl butyrate, methyl caproate, methyl caprylate, methyl decanoate, methyl cellulose acetate, ethylene glycol monobutyl ether ethyl Esters, propylene glycol monomethyl ether acetate, 1,2-diethoxyethane, tributyl phosphate, tricresyl phosphate or tripentyl phosphate; tetrahydrofuran, dipropyl ether, ethylene glycol Dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, propylene glycol dimethyl ether, ethoxy ethyl ether, 1,2-bis(2-diethoxy)ethane or 1,2-bis(2 -Methoxyethoxy) ethane and other ethers; acetic acid 2-(2butoxyethoxy)ethane and other ester ethers; 2-(2-methoxyethoxy)ethanol and other ether alcohols , Toluene, xylene, n-alkanes, isoalkanes, dodecylbenzene, turpentine, kerosene or light oil; nitrile such as acetonitrile or propionitrile; acetamide or N,N-dimethylformamide, etc. Amides; low molecular weight volatile silicone oil or volatile organic modified silicone oil and other silicone oils. These can be used alone or in combination of two or more kinds.

By using the solvent, the fluidity of the thermally conductive composition can be controlled. For example, the workability of the thermally conductive composition in paste form can be improved. In addition, the shrinkage during heating can promote sintering. Among the solvents, a solvent having a relatively high boiling point, preferably a solvent having a boiling point higher than the curing temperature, can be used to suppress the generation of voids in the adhesive layer obtained by heat-treating the thermally conductive composition. The boiling point of the high boiling point solvent may be, for example, 180°C to 450°C, or 200°C to 400°C.

Hereinafter, the manufacturing method of the thermally conductive composition of this embodiment is demonstrated. As a manufacturing method of the said thermally conductive composition, the method of mixing the said raw material component can be used. For mixing, a known method can be used, but for example, three rolls, a mixer, etc. can be used. In addition, the obtained mixture can be further defoamed. Regarding defoaming, for example, the mixture can be left standing under vacuum.

(Semiconductor device) The semiconductor device of this embodiment will be described. The semiconductor device includes: a substrate; and a semiconductor element on which an adhesive layer obtained by heat-treating the thermally conductive composition is mounted on the substrate. By using an adhesive layer with excellent heat dissipation and adhesion, a semiconductor device with excellent reliability can be realized.

In addition, the adhesive layer described above can be applied to various adherends. Specific examples of the adherend include semiconductor elements such as IC and LSI; base materials such as lead frames, BGA substrates, mounting substrates, and semiconductor wafers; heat dissipation members such as heat sinks and heat sinks.

Hereinafter, an example of a semiconductor device using the thermally conductive composition of this embodiment will be described. FIG. 1 is a cross-sectional view showing an example of the semiconductor device of this embodiment. The semiconductor device 100 of the present embodiment includes a substrate 30 and a semiconductor element 20 which is mounted on the substrate 30 via an adhesive layer 10 (wafer adhesive) as a heat-treated body of a thermally conductive composition. The semiconductor element 20 and the base material 30 are electrically connected via a bonding wire (bonding wire) 40 or the like, for example. In addition, the semiconductor element 20 is sealed with a sealing resin 50, for example.

The lower limit of the thickness of the adhesive layer 10 is preferably 5 μm or more, more preferably 10 μm or more, and even more preferably 20 μm or more. Thereby, the heat capacity of the heat-treated body of the thermally conductive composition can be increased, and the heat dissipation can be improved. In addition, the upper limit of the thickness of the adhesive layer 10 may be, for example, 100 μm or less, or may be 50 μm or less.

In FIG. 1, the base material 30 is, for example, a lead frame. At this time, the semiconductor device 20 is mounted on the wafer pad 32 or the substrate 30 via the adhesive layer 10. Furthermore, the semiconductor element 20 is electrically connected to the outer lead 34 (base material 30) via a bonding wire 40, for example. The base material 30 as the lead frame is composed of, for example, a 42 alloy and a Cu frame.

The substrate 30 may be an organic substrate or a ceramic substrate. As the organic substrate, for example, an epoxy resin, a cyanate ester resin, a maleimide resin, or the like is preferable. In addition, the surface of the substrate 30 may be coated with metal such as silver or gold, for example. Thereby, the adhesiveness of the adhesive layer 10 and the base material 30 can be improved.

FIG. 2 is a modification of FIG. 1, and is a cross-sectional view showing an example of the semiconductor device 100 of this embodiment. In the semiconductor device 100 of this modification example, the substrate 30 is, for example, an interposer. A plurality of solder balls 52 are formed, for example, on the other surface of the substrate 30 as an interposer on the side opposite to the surface on which the semiconductor element 20 is mounted. At this time, the semiconductor device 100 is connected to another wiring board via the solder balls 52.

(Method of manufacturing semiconductor device) An example of the manufacturing method of the semiconductor device of this embodiment will be described. First, the thermally conductive composition is coated on the substrate 30, and then, the semiconductor element 20 is placed thereon. That is, the base material 30, the thermally conductive composition, and the semiconductor element 20 are laminated in this order. The method of applying the thermally conductive composition is not limited, but specifically, a dispensing method (dispensing), a printing method, an inkjet method, etc. can be used. Next, by pre-curing and post-curing the thermally conductive composition, the thermally conductive composition is used as a heat-treated body (cured product). By heat treatment such as pre-hardening and post-hardening, the silver particles in the thermally conductive composition are aggregated to form a thermally conductive layer in which the interface between a plurality of silver particles disappears in the adhesive layer 10. Thereby, the substrate 30 and the semiconductor element 20 are bonded via the adhesive layer 10. Next, using the bonding wire 40, the semiconductor element 20 and the base material 30 are electrically connected. Next, the semiconductor element 20 is sealed with a sealing resin 50. Thereby, a semiconductor device can be manufactured.

The embodiments of the present invention have been described above, but these are examples of the present invention, and various configurations other than the above can be used. In addition, the present invention is not limited to the above-mentioned embodiment, and modifications, improvements, etc. within the scope of achieving the object of the present invention are included in the present invention. [Example]

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited at all by the description of these examples.

＜Thermally conductive composition＞ Based on the blending amounts shown in Table 1 below, the raw material components were mixed to obtain a varnish. According to the blending amounts shown in Table 1 below, the obtained varnish, solvent, and metal particles were blended and kneaded using a three-roll mill at room temperature to produce a paste-like thermal conductive composition.

Below, the information of the raw material components in Table 1 is shown. (Adhesive resin) •Epoxy resin 1: Bisphenol F type liquid epoxy resin (manufactured by Nippon Kayaku Co., Ltd., RE-303S)

(hardener) • Hardener 1: Phenolic resin with bisphenol F skeleton (solid at room temperature 25°C, manufactured by DIC Corporation, DIC-BPF)

(Acrylic particles) •Acrylic particles 1: Methacrylic resin particles (manufactured by SEKISUI PLASTICS CO., LTD., IBM-2) (monomer) • Acrylic monomer 1: 2-phenoxyethyl methacrylate (manufactured by KYOEISHA CHEMICAL Co., LTD., Light Ester PO) • Acrylic monomer 2: 1,4-cyclohexanedimethanol monoacrylate (manufactured by Mitsubishi Chemical Corporation., CHDMMA) • Acrylic monomer 3: Ethylene glycol dimethacrylate (manufactured by KYOEISHA CHEMICAL Co., LTD., Light Ester EG)

(Plasticizer) • Plasticizer 1: Allyl resin (manufactured by KANTO CHEMICAL CO., INC., a polymer of 1,2-cyclohexanedicarboxylic acid bis(2-propenyl) and propane-1,2-diol)

(Silicane coupling agent) • Silane coupling agent 1: 3-(trimethoxysilyl) propyl methacrylate (manufactured by Shin-Etsu Chemica. Co., Ltd., KBM-503P) • Silane coupling agent 2: 3-glycidoxypropyl trimethoxysilane (manufactured by Shin-Etsu Chemica. Co., Ltd., KBM-403E)

(Hardening accelerator) • Imidazole hardener 1: 2-phenyl-1H-imidazole-4,5-dimethanol (manufactured by SHIKOKU CHEMICALS CORPORATION, 2PHZ-PW)

(Polymerization initiator) • Radical polymerization initiator 1: Dicumyl peroxide (manufactured by Kayaku Akzo Corporation, Perkadox BC)

(Solvent) • Solvent 1: Butyl glycerol (BFTG)

(Metal particles) •Silver particles 1: Silver powder (manufactured by DOWA HIGHTECH CO., LTD., AG-DSB-114, spherical, D ₅₀ : 1μm) •Silver particles 2: Silver powder (Fukuda Metal Foil & Powder Co., Ltd. Manufacturing, HKD-16, flakes, D ₅₀ : 2μm) • Silver-coated resin particles 1: Silver-plated silicone resin particles (manufactured by Mitsubishi Materials Corporation, heat-resistant 2μm product, spherical, D ₅₀ : 2μm, specific gravity: 4.3, The weight ratio of silver is 80wt%, and the weight ratio of resin is 20wt%) •Silver coated resin particles 2: Silver-plated silicone resin particles (manufactured by Mitsubishi Materials Corporation, heat-resistant/surface treated 2μm product, spherical, D ₅₀ : 2μm , Specific gravity: 4.3, the weight ratio of silver is 80wt%, and the weight ratio of resin is 20wt%) •Silver coated resin particles 3: Silver-plated silicone resin particles (manufactured by Mitsubishi Materials Corporation, heat-resistant/surface treated 4μm product, spherical , D ₅₀ : 4μm, specific gravity: 3.8, the weight ratio of silver is 75wt%, and the weight ratio of resin is 25wt%) • Silver-coated resin particles 4: Silver-plated silicone resin particles (manufactured by Mitsubishi Materials Corporation, heat-resistant/surface Processing 10μm products, spherical, D ₅₀ : 10μm, specific gravity: 2.3, the weight ratio of silver is 50wt%, the weight ratio of resin is 50wt%) • Silver-coated resin particles 5: Silver-plated acrylic resin particles (SANNO Co., Ltd .Manufactured, SANSILVER-8D, spherical, D ₅₀ : 8μm, monodisperse particles, specific gravity: 2.4, the weight ratio of silver is 50wt%, the weight ratio of resin is 50wt%)

[Table 1] unit Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Comparative example 1 Varnish Adhesive resin Epoxy 1 Mass parts 50.0 50.0 50.0 50.0 50.0 50 50 hardener Hardener 1 20.0 20.0 20.0 20.0 20.0 20 20 Acrylic particles Acrylic particles 1 0.1 monomer Acrylic monomer 1 4.2 monomer Acrylic monomer 2 6.6 monomer Acrylic monomer 3 20.0 20.0 20.0 20.0 20.0 20 20 Plasticizer Plasticizer 1 20.0 20.0 20.0 20.0 20.0 20 20 Silane coupling agent Silane coupling agent 1 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Silane coupling agent 2 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Hardening accelerator Hardening accelerator 1 1.0 1.0 1.0 1.0 1.0 1 1 Polymerization initiator Free radical polymerization initiator 1 3.5 3.5 3.5 3.5 3.5 3.5 3.5 Thermal conductive composition Slurry Varnish Varnish quality% 12.8 12.8 12.8 12.8 12.8 12.8 12.8 10.9 Solvent Solvent 1 6.2 6.2 6.2 6.2 6.2 6.2 6.2 1.1 Metal particles Silver particles 1 27.1 27.1 27.1 37.7 27.1 27.1 32.4 38 Silver particles 2 23.9 23.9 23.9 33.3 23.9 23.9 28.6 50 Silver coated resin particles 1 30.0 Silver coated resin particles 2 30.0 Silver coated resin particles 3 30.0 Silver coated resin particles 4 10.0 30.0 20.0 Silver coated resin particles 5 30.0 total 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 Storage elastic modulus (25℃) E GPa 7.3 7.6 7.9 6.8 4.9 5.1 6.9 19.0 Thermal conductivity λ W/m•k 24.0 27.8 38.7 38.0 14.4 37.8 33.0 110.0 λ/(E ² ) 0.45 0.48 0.62 0.82 0.60 1.45 0.69 0.30 Resin content quality% 15.4 15.3 19.3 17.8 27.2 26.1 21.2 0.0 Temperature cycle test ○ ○ ○ ◎ ◎ ◎ ◎ ×

Using the obtained thermally conductive composition, the following physical properties were measured, and evaluation items were evaluated.

(Thermal conductivity) It took 60 minutes to heat up the obtained thermally conductive composition from 30°C to 200°C, and then heat-treated at 200°C for 120 minutes to obtain a heat-treated body with a thickness of 1 mm. Next, the laser flash method was used to measure the thermal diffusion coefficient α in the thickness direction of the heat-treated body. In addition, the measurement temperature was set to 25°C. Furthermore, the specific heat Cp was measured by differential scanning calorimetry (DSC) measurement, and the density ρ was measured in accordance with JIS-K-6911. Using these values, the thermal conductivity λ was calculated based on the following formula. The evaluation results are shown in Table 2 below. In addition, the unit is W/(m•K). Thermal conductivity λ[W/(m•K)]=α[m ² /sec]×Cp[J/kg•K]×ρ[g/cm ³ ]

(Storage elastic modulus) It took 60 minutes to heat up the obtained thermally conductive composition from 30°C to 200°C, and then heat-treated at 200°C for 120 minutes to obtain a heat-treated body. For the obtained heat-treated body, using a measuring device (manufactured by Hitachi High-Tech Science Corporation, DMS6100), the storage elastic modulus E (MPa) at 25°C was measured by dynamic viscoelasticity measurement (DMA) at a frequency of 1 Hz ).

(Observation of particle connection structure) Prepared copper lead frame and silicon wafer (length 2mm x width 2mm, thickness 0.35mm). Next, the obtained thermally conductive composition was coated on a silicon wafer so that the coating thickness became 25±10 μm, and a copper lead frame was placed on it. A laminated body was produced in which a silicon wafer, a thermally conductive composition, and a copper lead frame were sequentially laminated. Then, the obtained laminate was heated from 30°C to 200°C in the atmosphere over 60 minutes, and then heat treatment was performed at 200°C for 120 minutes to harden the thermally conductive composition in the laminate. Next, using a scanning electron microscope (SEM), the cross section of the heat-treated body of the thermally conductive composition in the laminate was observed, and the state was evaluated.

In all of Examples 1 to 7, it was confirmed that a silver particle connection structure was formed. In the cross-sectional image, it was also confirmed that a plurality of substantially circular resin particles were included in the silver particle connection structure, and the metal layer (silver layer) on the surface of the resin particle was connected to the silver particle connection structure. Furthermore, it was confirmed that the cured product of the binder resin was present in a portion other than the silver inside the silver particle connecting structure to cover the silver.

(Resin content) It took 60 minutes to heat up the obtained thermally conductive composition from 30°C to 200°C, and then heat-treated at 200°C for 120 minutes to obtain a heat-treated body. In the obtained heat-treated body, the binder resin and the resin component derived from the silver coating resin particles were measured in the following manner. Set the content of the resin component in the heat-treated body as the resin content (mass%) The resin content is calculated by measuring the weight of the obtained heat-treated body and subtracting the weight of silver contained from the weight.

(Temperature cycle test) The obtained thermally conductive composition was coated on a silver-plated substrate, and a 3.5×3.5mm silicon wafer was loaded from above (only in Comparative Example 1, the surface was silver-plated, otherwise it was not plated), and cost 60 The temperature was raised from 30°C to 200°C in minutes, and then heat treatment was performed at 200°C for 120 minutes to harden/join. The silicon wafer/substrate after bonding was sealed with a sealing material EME-G700ML-C (manufactured by Sumitomo Bakelite Co., Ltd.), and a sample was obtained. The obtained sample was put into a high temperature and high humidity bath at 85℃/60%RH, treated for 168 hours, and then reflowed at 260℃. Put the sample after reflow treatment into the temperature cycle tester TSA-72ES (manufactured by ESPEC CORP.), and it will be at 150°C for 10 minutes → 25°C for 10 minutes → -65°C for 10 minutes → 10 minutes at 25°C was set as 1 cycle, and 2000 cycles of treatment were performed. Then, SAT (ultrasonic flaw detection) was used to confirm whether there was peeling. In Table 1, those without peeling are marked as ○, and those with peeling are marked as x.

(Comparative Example 2) Mixed plasticizer (polybutadiene maleic anhydride adduct, manufactured by Cray Valley, RICOBOND1731) 2.43 parts by mass, acrylic resin (acrylic polymer, manufactured by TOAGOSEI CO., LTD., UG4035) 4.38 parts by mass, allyl resin (polymer of 1,2-cyclohexanedicarboxylic acid bis(2-propenyl) and propane-1,2-diol, manufactured by KANTO CHEMICAL CO., INC.) 6.57 parts by mass, hardening accelerator (dicyandiamine derivative, manufactured by ADEKA CORPORATION, EH-3636AS) 0.05 parts by mass, acrylic monomer (1.6 hexanediol dimethacrylate, manufactured by KYOEISHA CHEMICAL Co., LTD., Light Ester 1.6HX) 2.92 parts by mass, acrylic monomer (2-phenoxyethyl methacrylate, manufactured by KYOEISHA CHEMICAL Co., LTD., Light Ester PO) 8.03 parts by mass, coupling agent (3-(trimethyl methacrylate) (Oxysilyl) propyl ester, manufactured by Shin-Etsu Chemica. Co., Ltd., KBM-503P) 0.12 parts by mass, coupling agent (3-glycidoxypropyltrimethoxysilane, Shin-Etsu Chemica. Co., Ltd. manufactured, KBM-403E) 0.24 parts by mass, polymerization initiator (1,1-bis(1,1-dimethylethylperoxy)cyclohexane, manufactured by NOF CORPORATION., PERHEXA C ( S)) 0.24 parts by mass to obtain a varnish. 75.00 parts by mass of silver powder (manufactured by DOWA HIGHTECH CO., LTD., AG-DSB-114, spherical, D ₅₀ : 1μm) was blended into the obtained varnish, and kneaded using a three-roll mill at room temperature to produce Pasty thermal conductive composition. The thermal conductivity (λ) obtained by the above measurement method is 1W/m•K, and the storage elastic modulus (E) at 25°C is 3GPa. The calculated λ/(E ² ) is 0.11. It was found that compared with Comparative Example 2, the use of the thermally conductive compositions of Examples 1 to 7 can reduce the incidence of defects in semiconductor packages.

The thermally conductive compositions of Examples 1 to 7 show that the temperature cycleability is better than that of Comparative Example 1, and the heat dissipation property is better than that of Comparative Example 2. By using the thermally conductive composition of this embodiment, it is possible to realize a semiconductor device that stably exhibits high heat dissipation and has excellent durability during use.

This application claims priority based on Japanese Patent Application No. 2019-052707 filed on March 20, 2019, and uses all the contents disclosed therein.

100: Semiconductor device 10: Next layer 20: Semiconductor components 30: Substrate 32: Wafer pad 34: Outer lead 40: Bonding wire 50: sealing resin 52: Solder ball

The above-mentioned purpose and other purposes, features and advantages will be made clearer by the preferred embodiments described below and the accompanying drawings below.

[Fig. 1] is a cross-sectional view showing an example of the electronic device of this embodiment. [Fig. 2] is a cross-sectional view showing an example of the electronic device of this embodiment.

100: Semiconductor device

10: Next layer

20: Semiconductor components

30: Substrate

32: Wafer pad

34: Outer lead

40: Bonding wire

50: sealing resin

Claims (17)

A thermally conductive composition comprising: metal particles; a binder resin; and a monomer. The metal particles are sintered by heat treatment to form a particle-connected structure. The thermally conductive composition is used to measure the thermal conductivity according to the following step A The rate λ (W/mK) and the storage elastic modulus E (GPa) at 25°C measured according to the following step B satisfy the following formula (I), 0.35≤λ/(E ² )... formula (I) (step A) It took 60 minutes to heat up the thermally conductive composition from 30°C to 200°C, followed by heat treatment at 200°C for 120 minutes to obtain a heat-treated body with a thickness of 1 mm. For the heat-treated body obtained, a laser flash method was used to measure 25 Thermal conductivity λ (W/mK) at ℃, (Step B) It took 60 minutes to heat up the thermally conductive composition from 30°C to 200°C, and then heat-treated at 200°C for 120 minutes to obtain a heat-treated body. For the obtained heat treatment Body, using dynamic viscoelasticity measurement (DMA) at a frequency of 1Hz, to measure the storage elastic modulus E (MPa) at 25°C. Such as the thermal conductivity composition of claim 1, in which, With respect to 100% by mass of the aforementioned heat-treated body, the resin content in the heat-treated body obtained by the following steps is 10% by mass or more and 30% by mass or less, (step) This thermally conductive composition was heated up from 30°C to 200°C over 60 minutes, and then heat-treated at 200°C for 120 minutes to obtain a heat-treated body. Such as the thermal conductivity composition of claim 1, in which, The aforementioned metal particles include particles composed of one or more metal materials selected from the group consisting of silver, gold, and copper. Such as the thermal conductivity composition of claim 1, in which, The said binder resin contains 1 or more types chosen from the group which consists of an epoxy resin, an acrylic resin, and an allyl resin. Such as the thermal conductive composition of claim 1, which contains a hardener. Such as the thermal conductivity composition of claim 5, in which, The aforementioned curing agent includes a phenol resin-based curing agent or an imidazole-based curing agent. Such as the thermal conductivity composition of claim 1, in which, The aforementioned monomer includes one or more selected from the group consisting of a diol monomer, an acrylic monomer, an epoxy monomer, and a maleimide monomer. Such as the thermally conductive composition of claim 1, which contains a radical polymerization initiator. Such as the thermal conductivity composition of claim 1, which contains a silane coupling agent. Such as the thermal conductive composition of claim 1, which contains a plasticizer. Such as the thermal conductive composition of any one of claims 1 to 10, wherein: The aforementioned metal particles include metal-coated resin particles and particles made of metal. Such as the thermal conductivity composition of claim 11, in which, The specific gravity of the aforementioned metal-coated resin particles is 2 or more and 10 or less. The thermally conductive composition according to claim 11, wherein the average particle diameter D ₅₀ of the metal-coated resin particles is 0.5 μm or more and 20 μm or less. Such as the thermal conductivity composition of claim 11, in which, In 100% by mass of the metal particles, the content of the aforementioned metal-coated resin particles is 1% by mass or more and 50% by mass or less. Such as the thermal conductivity composition of claim 11, in which, The resin material constituting the resin particles in the metal coating resin particles includes one or two or more selected from the group consisting of silicone, acrylic, phenol, polystyrene, melamine, polyamide and polytetrafluoroethylene. Such as the thermal conductivity composition of claim 1, which contains a solvent. A semiconductor device including: Substrate; and A semiconductor element in which an adhesive layer obtained by heat-treating the thermally conductive composition of any one of claims 1 to 16 is mounted on the aforementioned substrate.

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